Vacuum process apparatus and method of operating the same

ABSTRACT

A vacuum process apparatus includes a plurality of cassettes for holding samples, a transporter which transports the samples, a plurality of vacuum process chambers each for processing samples one by one, an evacuator which evacuates the vacuum process chambers, and a load chamber and an unload chamber communicating with the vacuum process chambers. An apparatus controller is provided for controlling transporting and processing of the samples. The apparatus controller measures a time period for transporting each of the samples and a processing time period for processing a sample in each of the vacuum process chambers, and determines a next order of extraction of the samples from the plurality of cassettes based on the measured time periods.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This is a continuation of U.S. application Ser. No. 09/526,206,filed Mar. 15, 2000, the subject matter of which is incorporated byreference herein.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a vacuum process apparatuscomprising a control means for determining an order of loading samplesof the vacuum process apparatus having a plurality of process chambersand a method of operating the vacuum process apparatus. Moreparticularly, the invention relates to a vacuum process apparatus and amethod of operating the vacuum process apparatus, which can improve theefficiency of processing samples in the operation of parallel processesusing a plurality of process chambers.

[0003] A vacuum process apparatus having a control means for determiningthe order of loading samples into a plurality of process chambers isdisclosed in Japanese Patent Application Laid-open No.10-189687. Thisvacuum process apparatus has a system connecting a plurality of processchambers in which process scheduling is performed based on a priorityorder of the samples to be processed.

[0004] Further, a vacuum process apparatus for performing processing inparallel using a plurality of process chambers is disclosed in JapanesePatent Application Laid-open No.63-133532. In a case where processing isperformed in the vacuum process apparatus of a system connecting aplurality of process chambers to a transfer chamber in parallel, samplesare loaded in the order of loading samples to the two process chambersso that the numbers of the samples from two sample cassettes becomeequal to each other.

[0005] In the case where processing is performed in a plurality ofprocess chambers in parallel, since the processing time will not alwaysbe equal in all of the process chambers, even if samples are loaded inthe order of loading samples to the two process chambers so that thenumbers of the samples from two sample cassettes become equal to eachother, there is a problem in that useless waiting time occurs in loadingthe samples into the process chambers.

SUMMARY OF THE INVENTION

[0006] An object of the present invention is to provide a vacuum processapparatus with the aim of improving the efficiency of sample processingin the overall vacuum process apparatus in operation of parallelprocessing using a plurality of process chambers and a method ofoperating the vacuum process apparatus.

[0007] In order to attain the foregoing object, the present invention ischaracterized by a vacuum process apparatus comprising a plurality ofcassettes for containing samples; a transporting means for transportingsaid samples; a plurality of vacuum process chambers each for processingsaid samples one by one; an evacuation means for evacuating said vacuumprocess chambers; a load chamber and an unload chamber communicatingwith said vacuum process chambers; and an apparatus control means forcontrolling transporting and processing of said samples, wherein

[0008] said apparatus control means measures a time period during whicheach of said samples is transported and a processing time period in eachof said vacuum process chambers, and determines the next extractingorder of said samples from said plurality of cassettes based on saidmeasured time periods.

[0009] Another feature of the present invention involves provision of avacuum process apparatus comprising a plurality of cassettes forcontaining samples; a transporting means for transporting said samples;a plurality of vacuum process chambers each for processing said samplesone by one; an evacuation means for evacuating said vacuum processchambers; a load chamber and an unload chamber communicating with saidvacuum process chambers; and an apparatus control means for controllingtransporting and processing of said samples, wherein

[0010] said apparatus control means calculates a required time untilcompletion of preparation of the start of processing of a newly loadedsample using a time period of sample loading to and a time period ofsample unloading from each of said vacuum process chambers, and aprocessing time period of each of the samples, and loads a sample from acassette corresponding to a vacuum process chamber having the shortestrequired time among said vacuum process chambers to said vacuum processchamber.

[0011] Another feature of the present invention involves provision of avacuum process apparatus comprising a plurality of cassettes forcontaining samples; a transporting means for transporting said samples;a plurality of vacuum process chambers each for processing said samplesone by one; an evacuation means for evacuating said vacuum processchambers; a load chamber and an unload chamber communicating with saidvacuum process chambers; and an apparatus control means for controllingtransporting and processing of said samples, wherein said apparatuscontrol means comprises:

[0012] a transporting and processing time measuring means for measuringand calculating a time period of sample loading to and a time period ofsample unloading from each of said vacuum process chambers, and a sampleprocessing time period in each of said vacuum process chambers;

[0013] a sample processing waiting time estimating means for calculatingand estimating a required time until completion of preparation of thestart of processing of a newly loaded sample using said time period ofsample loading to and said time period of sample unloading from and saidsample processing time period in each of said vacuum process chambers;

[0014] a sample processing order determining means having a function todetermine a next extracting order of said samples based on data on saidtime period of sample loading to and said time period of sampleunloading from and said waiting time period obtained; and

[0015] a sample transporting and processing control means having afunction to control the overall vacuum process apparatus so as toperform sample processing and sample transporting based on the resultdetermined by said sample processing order determining means.

[0016] The vacuum process apparatus in accordance with the presentinvention selects a vacuum process chamber among the plurality of vacuumprocess chambers which has the shortest required time period fromcompletion of sample processing under way now to completion ofpreparation to load a new sample. That is, in the vacuum processapparatus performing processing in parallel using a plurality of vacuumprocess chambers, in order to shorten the waiting time period untilloading of a sample transported to the vacuum process apparatus into thevacuum process chamber, it is necessary to select a vacuum processchamber among the plurality of vacuum process chambers which has theshortest required time period from completion of sample processing underway now to completion of preparation to load a new sample.

[0017] According to the vacuum process apparatus in accordance with thepresent invention, the order of processing samples is determined bytaking the waiting time period into consideration. Therefore, the sampleprocessing efficiency can be improved because a vacuum process chamberseries capable of fast processing can process second and third samples,while a process chamber series of slow processing is processing a firstsample.

[0018] According to the vacuum process apparatus in accordance with thepresent invention, the waiting time period in the vacuum processapparatus can be minimized. Further, it is possible to shorten the timeperiod from extracting a sample from a sample cassette and performingprocessing to returning the sample to the cassette.

[0019] Furthermore, since the time period for completing processing foreach sample can be shortened, the processing time period for one samplecassette can be shortened.

[0020] Still further, by shortening the time period of processing for afirst sample cassette, the timing to start processing of a second samplecassette can be made earlier. Therefore, there is an effect in that itis possible to improve the sample processing efficiency of the overallvacuum process apparatus per unit time.

BRIEF DESCRIPTION OF DRAWINGS

[0021]FIG. 1 is a diagram showing an example of the system structure ofa vacuum process apparatus to which the present invention is applied.

[0022]FIG. 2 is a diagram showing an example of a functional structureof the apparatus control means of FIG. 1.

[0023]FIG. 3(A) and FIG. 3(B), when combined, provide a flowchartshowing process operation of calculating sample processing andtransporting time.

[0024]FIG. 4(A) and FIG. 4(B), when combined, provide a flowchart ofwaiting time estimation processing which calculates a required timeperiod until starting of processing in each process chamber.

[0025] FIGS. 5(A) and 5(B) are flowcharts showing the sequences oftransportation and processing of a sample, respectively.

[0026]FIG. 6 is a chart showing timing of sample processing in a case ofa sample loading procedure in accordance with the present invention.

[0027]FIG. 7 is a chart showing timing of sample processing in a case ofa sample loading procedure in the prior art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] An embodiment of the present invention will be described belowwith reference to the drawings. FIG. 1 shows an example of the systemstructure of a vacuum process apparatus to which the present inventionis applied. The vacuum process apparatus of FIG. 1 comprises fourprocess chambers 8 to 11, representing a first process chamber to afourth process chamber, and three sample cassettes 1 to 3. A samplecontained in the sample cassette 2 or the sample cassette 3 is extractedby an atmospheric transporting robot 4 and is transported to a load lockchamber 6 through an orientation flat adjusting unit 5. The load lockchamber 6 is capable of communicating with a vacuum transporting chamber13 in a vacuum state by switching between the atmospheric state and avacuum state. In the vacuum transporting chamber 13, a sample in theload lock chamber 6 is transported to any one of the process chambers 8to 11 already in a vacuum state by a vacuum transporting robot 7.

[0029] The samples are processed in the process chambers 8 to 11, and,after completion of processing, the processed samples are transported toan unload lock chamber 12 by the vacuum transporting robot 7. Similar tothe load lock chamber 6, the unload lock chamber 12 can be switchedbetween the atmospheric state and the vacuum state. By switching theunload lock chamber 12 to the atmospheric state, the samples extractedfrom the unload lock chamber 12 by the atmospheric transporting robot 4are returned to the sample cassettes 1 to 3.

[0030] The series of process described above is controlled by anapparatus control means 15 composed of a microcomputer through aninput/output processing means 14. The apparatus control means 15comprises a CPU, a memory such as a RAM, a ROM or the like, an externalmemory means, an input/output control means, an input/output means andso on. The apparatus control means 15 controls operation of the vacuumprocess apparatus based on programs and commands pre-stored in the ROMand the like, various kinds of data stored in the memory, andinformation from various kinds of sensors and counters sensing the stateof the vacuum process apparatus.

[0031] An operating procedure input means 16, such as a personalcomputer, is connected to the apparatus control means 15, and theprograms and commands for executing various kinds of vacuum processingand various kinds of data are input to the apparatus control means 15,and recorded and stored in the memories such as the RAM, the ROM and theexternal memory unit.

[0032]FIG. 2 shows an example of the functional structure of theapparatus control means 15 described above. The apparatus control means15 comprises a transporting and processing time measuring means 300 forcalculating by measuring time periods of transporting a sample in thevacuum process apparatus and time periods of processing a sample in theprocess chamber, that is, a time period of sample loading to and a timeperiod of sample unloading from each of the process chambers and asample processing time period; a sample processing waiting timeestimating means 400 for calculating and estimating a time period untilcompletion of preparation to start processing of a newly loaded sampleusing the time period of sample loading and the time period of sampleunloading and the sample processing time period described above; asample processing order determining means 500 having a function todetermine the next extracting order of the samples from the cassettesbased on data indicating the transporting and the processing timeperiods and the waiting time period obtained above; and a sampletransporting and processing control means 600 having a function tocontrol the overall vacuum process apparatus so as to process andtransport the samples based on the result determined by the sampleprocessing order determining means 500.

[0033] The time period, from the time of loading a new sample untilcompletion of loading the new sample into each of the process chambers,can be obtained by calculating a time period until the new sample isready to be loaded into the process chamber, taking into considerationthe remaining time period of sample processing under way now, the timeperiod needed for unloading the processed sample, and the time periodduring which the processed sample must wait to be extracted due to theextraction of another sample to be transported, depending on thestructure of the apparatus.

[0034] Procedures for loading and processing of samples in accordancewith the present invention will be described below with reference toFIG. 3 to FIG. 5.

[0035] Initially, the transporting and processing time measuring means300 will be described. It is assumed that the transporting andprocessing time measuring means 300 calculates in the case where sampleprocessing is performed in the first process chamber 8 for the samplecassette 1 and the third process chamber 10 for the sample cassette inparallel. The time period until completion of preparation to the startof processing of a next sample in the first process chamber 8 is T1, andthe time period until completion of preparation to the start ofprocessing of a next sample in the third process chamber 10 is T2.

[0036] Letting the total time period needed for processing the sampleunder way in the process chamber 8 be Te1 and the elapsed time period ofthe processing in the process chamber 8 be Tz1, the remaining timeperiod Tn1 of processing in the process chamber 8 can be calculated fromthe following equation.

Tn1=Te1−Tz1

[0037] Similarly, the remaining time period Tn2 of processing in theprocess chamber 9 can be calculated from the following equation.

Tn2=Te2−Tz2

[0038] The time period required for processing one sample in the processchamber can be obtained by measuring and storing a time period from thebeginning to the completion of the sample processing previouslyexecuted. The time period required for processing the first sample canbe obtained by referring to data on sample processing previouslyexecuted using another sample cassette. However, if there is no data onthe measured processing time period because processing has never beenexecuted before, the time period required for processing the firstsample is obtained by performing a calculation taking time period datain processing data for performing sample processing into consideration.

[0039] The time period calculation described above will be describedwith reference to the flowchart of FIG. 3(A) and FIG. 3(B). Theprocessing shown in this flowchart is a cyclic processing executed every0.1 second and is used for required time calculation processing to judgethe waiting time estimating processing described above by alwaysmeasuring a time period of each transporting processing and a sampleprocessing time period in each of the process chambers.

[0040] Initially, it is judged whether or not transporting of the samplefrom the load lock chamber 6 to the process chamber 8 is under way (Step302). If the transporting of the sample from the load lock chamber 6 tothe process chamber 8 is under way, the transporting time from the loadlock chamber 6 to the process chamber 8 is counted (Step 304).

[0041] Next, it is judged whether or not transporting of a sample fromthe process chamber 8 to the process chamber 9 is under way (Step 306).If transporting of a sample from the process chamber 8 to the processchamber 9 is under way, the transporting time from the process chamber 8to the process chamber 9 is counted (Step 308).

[0042] Further, it is judged whether or not transporting of a samplefrom the load lock chamber 6 to the process chamber 10 is under way(Step 310). If transporting of the sample from the load lock chamber 6to the process chamber 10 is under way, the transporting time from theload lock chamber 6 to the process chamber 10 is counted (Step 312).

[0043] Further, it is judged whether or not transporting of a samplefrom the process chamber 10 to the process chamber 11 is under way (Step314). If transporting of the sample from the process chamber 10 to theprocess chamber 11 is under way, the transporting time from the processchamber 10 to the process chamber 11 is counted (Step 316).

[0044] Next, it is judged whether or not transporting of the sample fromthe process chamber 9 to the unload lock chamber 12 is under way (Step318). If transporting of the sample from the process chamber 9 to theunload lock chamber 12 is under way, the transporting time from theprocess chamber 9 to the unload lock chamber 12 is counted (Step 320).

[0045] Further, it is judged whether or not transporting of the samplefrom the process chamber 11 to the unload lock chamber 12 is under way(Step 322). If transporting of the sample from the process chamber 11 tothe unload lock chamber 122 is under way, the transporting time from theprocess chamber 11 to the unload lock chamber 12 is counted (Step 324).

[0046] Next, it is judged whether or not processing of the sample isunder way in the process chamber 8 (Step 326). If processing of thesample is under way in the process chamber 8, the sample processing timein the process chamber 8 is counted (Step 328).

[0047] Similarly, it is judged whether or not processing of the sampleis under way in each of the process chambers 9 to 11 (Step 330 to Step338). If processing of the sample is under way in a process chamber, thesample processing time in each of the process chambers is counted (Step332 to Step 340).

[0048] The sample processing waiting time estimating means 400 and thesample processing order determining means 500 will be described. Thewaiting time period estimating processing for calculating a requiredtime period to start processing in each of the process chambers 8 to 11when a next sample is loaded in the process chamber, and transportationof each of the samples is started based on the calculated result.

[0049] For a sample processing under way now, the elapsed time periodcan be obtained by referring to time data of a program for measuring theprocessing time of the process chamber. Further, a calculation isexecuted by adding a time period Tout1, which is necessary for unloadingthe sample from the process chamber 8 after completing sample processingin the process chamber 8, a time period Tin1, which is necessary forloading a new sample in the process chamber 8 and a remaining timeperiod Tn1 for processing the sample.

[0050] From the above, the time period T1 until completion ofpreparation to the start of processing of the new sample in the processchamber 8 can be obtained from the following equation.

T1=Tn1+Tout1+Tin1

[0051] Similarly, the time period T2 for the process chamber 9 can beobtained from the following equation.

T2=Tn2+Tout2+Tin2

[0052] FIGS. 4(A) and 4(B) constitute a flowchart of the waiting timeestimation processing which calculates a required time period untilstarting of processing in each of the process chambers 8 to 11 describedabove. Referring to FIG. 4(A), it is judged whether or not processing inthe process chamber 8 is under way (Step 401). In a case where theprocessing in the process chamber 8 is under way, assuming that thesample to be extracted next is in the sample cassette 1, a time period(T1) until processing of this sample ready for starting in the processchamber 8 is calculated from the following equation (Step 402).

T1=remaining processing time in the process chamber 8 (Tn1)+transportingtime from the process chamber 8 to the process chamber 9 (Tout1)+loadingtime from the load lock chamber 6 to the process chamber 8 (Tin1)

[0053] Next, it is judged whether or not the sample of the samplecassette 1 is in the load lock chamber 6 (Step 404).

[0054] In a case where the sample of the sample cassette 1 is in theload lock chamber 6, assuming that the sample to be extracted next is inthe sample cassette 1, a time period (T1) until processing of thissample ready for starting in the process chamber 8 is calculated fromthe following equation (Step 406).

T1=T1+processing time in the process chamber 8 (Te1)+transporting timefrom the process chamber 8 to the process chamber 9 (Tout1)+loading timefrom the load lock chamber 6 to the process chamber 8 (Tin1)

[0055] Next, it is judged whether or not the sample of the samplecassette 1 is in the orientation flat adjusting unit 5 (Step 408).

[0056] In a case where the sample of the sample cassette 1 is in theorientation flat adjusting unit 5, assuming that the sample to beextracted next is the sample cassette 1, a time period (T1) untilprocessing of this sample ready for starting in the process chamber 8 iscalculated from the following equation (Step 410).

T1=T1+processing time in the process chamber 8 (Te1)+transporting timefrom the process chamber 8 to the process chamber 9 (Tout1)+loading timefrom the load lock chamber 6 to the process chamber 8 (Tin1)

[0057] Further, it is judged whether or not processing in the processchamber 10 is under way (Step 4121).

[0058] In a case where the processing in the process chamber 10 is underway, assuming that the sample to be extracted next is in the samplecassette 2, a time period (T2) until processing of this sample ready forstarting in the process chamber 10 is calculated from the followingequation (Step 414).

T2=remaining processing time in the process chamber 10(Tn2)+transporting time from the process chamber 10 to the processchamber 11 (Tout2)+loading time from the load lock chamber 6 to theprocess chamber 10 (Tin2)

[0059] Next, it is judged whether or not the sample of the samplecassette 2 is in the load lock chamber 6 (Step 416).

[0060] In a case where the sample of the sample cassette 2 is in theload lock chamber 6, assuming that the sample to be extracted next is inthe sample cassette 2, a time period (T2) until processing of thissample ready for starting in the process chamber 10 is calculated fromthe following equation (Step 418).

T2=T2+processing time in the process chamber 10 (Te2)+transporting timefrom the process chamber 10 to the process chamber 11 (Tout2)+loadingtime from the load lock chamber 6 to the process chamber 10 (Tin2)

[0061] Next, it is judged whether or not the sample of the samplecassette 1 is in the orientation flat adjusting unit 5 (Step 420).

[0062] In a case where the sample of the sample cassette 1 is in theorientation flat adjusting unit 5, assuming that the sample to beextracted next is in the sample cassette 1, a time period (T2) untilprocessing of this sample ready for starting in the process chamber 10is calculated from the following equation (Step 422).

T2=T2+processing time in the process chamber 10 (Te2)+transporting timefrom the process chamber 10 to the process chamber 11 (Tout2)+loadingtime from the load lock chamber 6 to the process chamber 10 (Tin2)

[0063] In a case where a waiting time period for sample transportationoccurs due to the construction of the apparatus, it is judged in takingsample transporting order protocol into consideration whether or not thewaiting time period occurs. If the waiting time period occurs, thewaiting time period can be obtained by calculating another transportingtime period and another sample processing time period which in the causeof the waiting time period. By adding all the time periods obtained intaking these into consideration, the time period until completion of thepreparation of performing the next sample processing in the processchamber can be calculated.

[0064] Next, the time period until starting to process the sample of thesample cassette 1 (T1) is compared with the time period until startingto process the sample of the sample cassette 2 (T2) (Step 424). If thetime period until starting to process the sample of the sample cassette1 (T1) is smaller, the sample is extracted from the sample cassette 1 tostart transporting the sample to the orientation flat adjusting unit(Step 426). On the contrary, if the time period until starting toprocess the sample of the sample cassette 2 (T2) is smaller, the sampleis started to be extracted from the sample cassette 2 (Step 428).

[0065] By comparing T1 and T2 obtained from calculation as describedabove, the sample is extracted from the sample cassette 1 to betransported to the load lock chamber when T1≦T2, and the sample isextracted from the sample cassette 2 to be transported to the load lockchamber when T1>T2.

[0066] In the above description of the embodiment, the order in whichthe samples are extracted is determined using time periods measured justbefore processes are executed, as they are. However, the order ofextraction of the samples may be determined using averaged values ofmeasured time periods obtained in the past.

[0067] In this case, the order of extraction of the samples can bedetermined similarly to the above-mentioned processing by replacing theloading, the transporting and the processing time periods describedabove with time periods obtained by processing to obtain average valuesusing data accumulated in a required time calculation data area, as willbe described later with reference to FIG. 5. The reason why the averagevalues are used is that there are variations in the loading, thetransporting and the processing time periods, and accordingly the sampleprocessing efficiency per unit time of the overall vacuum processapparatus can be improved by using the average values.

[0068] Sequences of processing and transportation of the sample will bedescribed with reference to FIG. 5(A), which shows a transportingsequence from the load lock chamber 6 to the process chamber 8. A sampletransporting count timer value is cleared, and a flag of “transportationunder way from the load lock chamber to the process chamber 1” is set(Step 502).

[0069] Next, the sequence of sample transportation is executed (Step504). Next, the flag of “transportation under way from the load lockchamber to the process chamber 1” is cleared (Step 506). Further, thevalue of the transporting count timer is stored in the required timecalculation data area (Tin1) (Step 508).

[0070]FIG. 5(B) shows a sample processing sequence in the processchamber 8. Initially, a sample transporting count timer value iscleared, and a flag of “sample processing under way in the processchamber 8” is set (Step 512). Next, the sequence of sample processing isexecuted (Step 514).

[0071] Next, the flag of “sample processing under way in the processchamber 8” is cleared (Step 516). Further, the value of the sampleprocessing count timer is stored in the required time calculation dataarea (Te1) (Step 518).

[0072] The time periods required for loading and unloading samples aremeasured every time transporting processing is performed, and the timedata is stored. By doing so, the time data can be stored by measuringthe transporting process time periods from the beginning of astarting-up stage accompanied by installation of the vacuum processapparatus. Therefore, since the data is always accumulated at the startof the sample processing, the problem of lack of data never occurs.

[0073] The effects of the embodiment in accordance with the presentinvention will be described with reference to FIG. 6 and FIG. 7. Here,discussion will be made of a process in which the processing in theprocess chamber 10 among the four process chambers 8 to 11 takes alonger time than the processing in the other process chambers. FIG. 6 isa chart showing timing of the sample processing based on the order ofsample loading in accordance with the present invention. When thesamples are loaded from the two sample cassettes 1, 2 to the processchambers, useless waiting time periods hardly occur.

[0074] On the other hand, FIG. 7 is a chart showing timing of sampleprocessing based on the order of sample loading in a conventionalmethod. Even if the samples are loaded to the process chambers so thatnumbers of samples extracted from the two sample cassettes 1, 2 becomeequal to each other, long waiting time periods occur in loading andunloading of the samples to and from the process chamber 10 becausethere are differences in the processing time periods between the processchamber 10 and the other process chambers.

[0075] It can be understood from the comparison between FIG. 6 and FIG.7 that the vacuum process apparatus according to the present inventionclearly has an effect to improve the sample processing efficiency,because a process chamber series which has a fast processing time canprocess a second sample and a third sample, while a process chamberseries which has a slow processing time is processing a first sample.

What is claimed is:
 1. A vacuum process apparatus comprising a pluralityof cassettes for holding samples; a transporter which transports saidsamples; a plurality of vacuum process chambers each for processingsamples one by one; an evacuator which evacuates said vacuum processchambers; a load chamber and an unload chamber communicating with saidvacuum process chambers; and apparatus controller which controlstransporting and processing of said samples, wherein said apparatuscontroller measures a time period for transporting each of said samplesand a processing time period for processing a sample in each of saidvacuum process chambers, and determines a next order of extraction ofsaid samples from said plurality of cassettes based on said measuredtime periods.